Fluid-operated machine and safety control system therefor

ABSTRACT

A fluid-operated machine having members for applying pressure to a workpiece placed therebetween by an operator, which machine is equipped with safety controls to prevent trapping of the hands of the machine operator, or of another person, between the members during closing of the same upon the workpiece. A garment-pressing machine employing a valve-controlled conduit system with the safety controls included, and without detracting from the numerous operating capabilities required of a garment pressing machine, is employed to illustrate the invention.

United States Patent Richterkessing [54] FLUID-OPERATED MACHINE ANDSAFETY CONTROL SYSTEM THEREFOR [72] Inventor: Frank H. Richterkessing,1200 Park Hills Drive, Louisville, Ky. 40207 [22] Filed: May 12, 1969[21] Appl. No.: 823,722

[52] US. Cl ..38/4l, 192/131 [51] Int. Cl. v v ..D06f71/00 [58]fieldofSearch ..192/130, 131; 38/39-41; 100/53 [56] References CitedUNITED STATES PATENTS 1,874,876 8/1932 Braun ..192/131 2,265,449 12/1941Raynolds ..38/41X [451 Feb. 8, 1972 2,451,845 10/1948 Lorhitzo et al...38/4l 2,971,281 2/1961 Neckel ..38/4l Primary Examiner-.lordanFranklin Assistant Examiner-Geo. V. Larkin Attorney-John D. Rice andWilliam E. Sherwood [57] ABSTRACT A fluid-operated machine havingmembers for applying pressure to a workpiece placed therebetween by anoperator, which machine is equipped with safety controls to preventtrapping of the hands of the machine operator, or of another person,between the members during closing of the same upon the workpiece.

A garment-pressing machine employing a valve-controlled conduit systemwith the safety controls included, and without detracting from thenumerous operating capabilities required of a garment pressing machine,is employed to illustrate the invention.

7 Claims, 5 Drawing Figures PATENTEDFEB 8m 3.640.007

sum 1 nr 4 INVENTOR FRANK H. RICHTERKESSNG BY ME. QMA

ATTORNEY PATENTED 1972 3.640.007

SHEET 2 BF 4 INVENTOR 1. Z FRANK H.RICHTERKESS\NG BY 1 7 3mm? ATTORNEYPATENYEBIEB 8M2 INVENTOR FRANK H. DJC HTERKESSNG BY W75, 2 0mg ATTORNEYmsmwm em 3640.007

SHEET t Of 4 1 l J59 N INVENTOR FRANK H WCHTERKESSNG BY 0 Siam/wkATTORNEY BACKGROUND OF THE INVENTION Legislation in many jurisdictionsnow requires the use of safety controls on power-operated machines forprotecting the hands of an operator, and many patents have been grantedon the two-hand safety control concept.

However, the equipping of a machine with such controls frequentlyimposes limitations upon the full capability of use of the machine, orit may embody a complex or expensive arrangement of parts, and, in somecases, may employ an arrangement that may permit the circumventing of.the safety controls by experimentation or by carelessness on the part ofthe operator.

While the present invention is adapted for use on many types ofpower-operated machines, it is particularly well suited for use onvarious types of garment-pressing machines required to perform a varietyof pressing operations on garments of various types. For example, whilekeeping his hands protected, the operator may be required to effectclosing of I 1 the press head, either to apply a light or a heavierpressure upon the garment, and either to lock, or not to lock, the presshead in pressure engagement with the garment.

Also, the operator may be required to operate the machine whilesimultaneously steaming the garment, and to subsequently effect arelease of the press head from pressure engagement with the garment. Allof these, and other operations, may be required to be performed by theoperator while another person is present at the machine. Therefore, thepresent invention has for its object, not only the protection of theoperator, but any other person that may be present during suchoperations.

SUMMARY The invention relates to a safety control system for a fluidoperated machine having a valve controlled conduit system connected to asource of pressure fluid, and to a first actuator or cylinder 23employed to close cooperative members upon a workpiece placedtherebetween by an operator. Preferably, a second actuator or cylinder24, working in conjunction with the first actuator 23, is employed toclose the members with a heavier pressure than that effected by thefirst actuator 23 alone.

The conduit system has a main valve 32 whose position determines whetherfluid can or cannot flow to the actuators 23 and 24; the pilot actuator33 of the valve 32 being connected for pressurization, or for venting toexhaust, as determined by the manual positioning of a manual detentvalve 94.

The safety means includes a master valve 40 adapted to receive operatingfluid jointly from spaced left-hand an righthand manually operablevalves 18 and 19, and to pass fluid from the master valve 40, through acontrol valve 34 to the pilot actuator 33 of the main supply valve 32,when the control valve 34 is in its operated position. However, theaforesaid flow of fluid from the master valve 40 can be initiated onlywhen the two manually operated valves 18 and 19 are operated within apredetermined time interval of each other, and moreover, the fluidpassing from the master valve 40, through the control valve 34, can beattained only when a two way bleed valve 76 in the system is maintainedclosed; the bleed valve 76 opening when a supplementary safety means 72,73, 74, 75, primarily for the protection of a person other than theoperator, is displaced from a predetermined position, by a personoccupying a dangerous position adjacent the cooperative members of themachine.

Among the objectives of the invention are the providing of a fluidoperated machine having means for protecting the hands of the operator,and of other persons present at the machine during operation of themachine; an improved valve controlled conduit system for a fluidoperated machine incorporating safety means for the operator, and whichsystem enables the operator optionally to lock, or to prevent lockingof, a

of the valves in the conduit system when employed with the press of FIG.1.

, FIG. 3 is a schematic view of the air circuit in the conduit system ofFIG. 2 with the valve members identified in accordance with the USASsymbols authorized by the National Fluid Power Association.

FIG. 4 is a cross sectional view of the master safety valve,

and

FIG. 5 is a diagrammatic view showing the positioning of the safety barwith respect to the buck and head of the press of FIG. 1.

Referring first to FIG. 1, a conventional garment press, with which thepresent invention is particularly well suited for' use, includes theusual baseplate 10, buck column 11, head column 12, and yoke 13pivotally mounted on the head column. Steam connections forming no partof the present invention are provided for the press buck 14 attached tothe column 11 and for the press head 15. A table 16 with a protectivewall 17 at its rear edge is supported below the buck 14, and along andbelow its front edge separate deft-hand and right-hand manually actuatedvalves l8, 19 respectively (FIG.' 2) are located in spaced relation toeach other and are interposed in the conduit system of the invention foroperation in the manner later to be described.

The yoke 13 normally holds the press head 15 in elevated position bymeans of a pair of rods 26-2611 connected to the yoke and urgeddownwardly by counterbalance springs contained in cylindrical shells 20,21. A suitable oil check 22 is also connected to the yoke 13, and thisoil check serves to cushion, or control, the travel of the press head 15toward and away from the buck 14, so that a smooth engagement of thepress head with the buck is effected at the end of its closing travel,and likewise, a smooth arresting of the head movement is effected at theend of its opening travel.

Actuators or cylinders 23 and 24, employed to close the head 15 upon thebuck 14, are pivotally mounted upon the buck column 12, and eachcontains a piston having a piston rod pivotally attached to the yoke 13,to serve a purpose later to appear. v

A suitable means 25, carried by the rod 26 extending from thecounterbalancing spring, contained within ,the cylindrical shell 20, tothe yoke 13, is adapted to actuate a three-way, normally closed camvalve 27, when the head 15 approaches its closed position, as will bedescribed more completely later.

The valve-controlled conduit system receives regulated pressure fluid,for example, air at a pressure of approximately p.s.i.g., after passingthrough a filter '30, and a pressure regulator 31 equipped with an airgage. This regulated fluid pressure is directed to the inlet port of athree-way, normally closed valve 32, herein called the main valve, andthis valve may conveniently be the three-way, normally closed type250A-310-20, available from Humphrey Products, Kalamazoo, Mich.

The main valve 32 has a pilot actuator 33, and the exhaust port of themain valve 32 is preferably equipped with a suitable silencer ofmuffler.

The three-way, normally open valve 34, herein called the control valve,may conveniently be the three-way, normally open type l25A3-l l-20-60,also available from Humphrey Products.

The control valve 34 has a pilot actuator 35 with a line connection 36leading thereto from a line connection 46.

The cylinder, or outlet port of the control valve 34, is connected byline 37 to the pilot actuator 33 of the main control valve 32.

The inlet port of the control valve 34 receives fluid pressure via lines38a-38 herein called the third conduit, from the actuator or closingcylinder 23, when the piston within the closing cylinder 23 is movedbeyond the connections of line 38a thereto, which connection ispreferably located at a position where the surface of the head 15 isoperated to within approximately one-half inch of the surface of thebuck 14. Prior to the movement of the piston, to the aforesaid positionbeyond the aforesaid connection, the line 38a is vented to exhaust, oratmosphere, through the space above the piston in the cylinder However,the aforesaid pressurizing of lines 38a-38 is also dependent upon themanual setting of a three-way, normally open manual detent valve 94,which valve, when manually set in the position illustrated in FIG. 3,provides a continuous flow connection from the cylinder 23 to the inletport of the control valve 34. Thus, when the manual detent valve 94 ismanually set in its reverse position, the inlet port of the manualdetent valve 94, which is connected by lines 38a to the cylinder 23, isblocked, and the cylinder or outlet port of the manual detent valve 94,which is connected by line 38 to the inlet port of the control valve 34,is then continuously vented to the exhaust port of the manual detentvalve, and the outlet port of the manual detent valve may not bepressurized from the connection of line 38a with the cylinder 23. Theexhaust port of the manual detent valve is provided with a suitablemuffler or silencer.

The exhaust port of the control valve 34 is connected via line 39 to theoutletport in the body B of the master valve 40, and, as will bedescribed more fully later, the outlet port of the master valve 40 isnormally connected to exhaust within the master valve, and istransferred from exhaust to pressure, only when the master valve 40 isoperated properly by the respective left-hand and right-hand manuallyoperated valves 18 and 19, and only while the hands of the operatorretain the manually operated valves 18 and 19 continuously actuatedafter the master valve 40 is operated to transfer its outlet port froman exhaust condition to a pressurized condition.

A line 77, connecting the line 39, extends to the inlet port of a twowaybleed valve 76, normally held closed by a supplementary safety means,illustrated in FIGS. 1 and as a frame 72, 73, 74, 75, having rigid arms70 and 71, which supplementary safety means will be described morecompletely later, and the exhaust port of the two-way bleed valve 76 ispreferably equipped with a muffler or silencer.

Another circuit, leading from the pressure regulator 31, suppliesregulated fluid pressure through lines 41 and 42, to the respectiveinlet ports of the pair of three-way, normally closed manually operatedvalves 18 and 19 comprising the respective lefthand and right-handvalves heretofore mentioned. These valves which conveniently may be thethreeway, normally closed type MV5 available from Mead SpecialtiesCompany, Chicago, Ill., are each equipped with mufflers or silencers inthe exhaust ports thereof, and these valves are actuated by the operatorpressing upon rods housed in elongated tubes 43, 44, as seen in FIG. 2,which tubes extend upwardly from the front edge of the table 16. Theoutlet lines 45 and 46, leading from the respective outlet or cylinderports of the manually operable valves 18 and 19, lead to appropriateinlet ports in the body B of the master valve 40, and the connection 46is also connected to the line 36 leading to the pilot actuator of thecontrol valve 34, so that upon opening of the manually operated valve 19to pressurize the line 46, the pilot actuator of the control valve 34 ispressurized via line 36.

Referring now to FIG. 4, the master valve 40, which conveniently may bethe type 1868A2002 Logicair valve available from the Ross OperatingValve Company, Detroit, Mich., includes a valve body B with an interiorspace 50 therein communicating directly with the respective inlet portshaving lines 45 and 46 connected thereto.

Mounted for reciprocation in space 50 is a pass shuttle 51 adapted toclose either upon seat 52 or 53, depending upon its direction ofmovement. A timing orifice 54, of fixed size, leads from the space 50 toa timing chamber 55, which timing chamber has another communicationthereto from a passage 57, through a check valve space 56, having anormally closed check valve 58-mounted therein and spring biased to openwhen the passage 57 is pressurized at a pressure greater than thepressure in the timing chamber 55, thereby to equalize the pressure inthe timing chamber 55 with the pressure in passage 57.

The passage 57 communicates directly with the outlet port in the valvebody B to which the line 39 is attached, and communication of thepassage 57 with the exhaust port 59 in the valve body B is governed bythe positioning of the head portion 61, spaced from but attached to apiston portion 60, of a three-way, normally open valve built within thevalve body B of the master valve 40.

The piston portion 60 is exposed to fluid pressure in the timing chamber55, whereas the head portion 61 is exposed to fluid pressure in passage57. The head portion 61 is slightly larger than the passage 59a, whichprovides communication between the passage 57 and the exhaust port 59,and normally the head portion 61 blocks communication between thepassage 57 and the exhaust port 59.

Spaced from, but adapted to be blocked by the head portion 61, when thepiston 60 is operated in response to fluid pres sure of a predeterminedvalue in the timing chamber 55, is a single connection passage 62 havingtwo connecting branch passages 63 and 64, which branch passagescommunicate with the space 50 on opposite sides of the pass shuttle 51.

A check shuttle C, having equally sized and spaced heads 65 and 66, ispositioned and adapted to establish communication between the singlepassage 62, and one or the other, but not both simultaneously, of thebranch passages 63 or 64, depending upon the positioning of the checkshuttle C.

The diameter of the single passage 62, moreover, is less than thediameter of the passage 59a andlthe piston 60, thereby to provide anecessary area differential between the passage 62 and the piston 60,

From the foregoing it will be apparent that the function of the passshuttle 51 is to establish pressurization of the timing chamber 55 fromthe first of the two lines 45 or 46, when pressurized by reason ofeither sequential or simultaneous operation of the two manually operablevalves 18 and 19, whereas the function of the pass shuttle C is toestablish pressurization of the single passage 62 from the second of thetwo lines 45 or 46 when pressurized by reason of either sequential orsimultaneous operation of the two manually operable valves 18 and 19.

The relation of the size of the fixed timing orifice 54 to the volume ofthe timing chamber 55 is such as to provide pressurization of the timingchamber 55 to approximately 75 percent of the regulated inlet pressurefrom either of the inlet ports in the valve body B, connected by lines45 or 46, in approximately 1 second.

The piston 60 is arranged and adapted to operate in response to theaforesaid pressurization of the timing chamber 55, when the pressuretherein reaches the 75 percent level, and when the single passage 62 hasnot been pressurized, thereby to block the single passage 62, and tovent the passage 57, via passage 59a, to the exhaust port 59 in thevalve body B.

The relative area of the single passage 62, and the piston 60, is suchas to prevent an unblocking of the single passage 62 by the head portion61, should the single passage 62 be pressurized after the piston 60 hasoperated.

Likewise, the relative area of the head portion 61, and the piston 60,is such as to retain blocking of the passage 59a, communicating with theexhaust port 59, as long as pressure within the passage 57 remainseither greater than or equal to the pressure within the timing chamber55.

As hereinbefore described, the check valve 58 is spring biased to permitflow of air from passages 57 to the timing chamber 55, for the purposeof equalizing pressures therein. However, the biasing of the check valve58 is such as to prevent a flow of air from the timing chamber 55 to thepassage 57.

Therefore, after pressurization of the passage 57 is effected inresponse to proper operation of the two manually operable valves 18 and19, should the pressure in line 39, connecting the outlet port of themaster valve 40, be reduced either intermittently or for a longerduration, the pressure in the passage 57 will be reduced, and thepressure in the timing chamber 55 will then exceed the pressure in thepassage 57, which will immediately result in an operation of the piston60 to provide blocking of the single passage 62 by the head portion 61,and to vent the passage 57 to exhaust, via passage 59a to the exhaustport 59 in the master valve 40.

Thus, the normally closed bleed valve 76 is provided to vent the line 39to exhaust, whenever the safety means, consisting of frame members 72,73, 74, and 75 is operated to open the bleed valve 76.

The pass shuttle 51 and the check shuttle C, within the master valve 40,are illustrated schematically in FIG. 4 as having pressure applied toone inlet port of the master valve 40 via line 46. Since the three-way,normally open valve, including the head portion 61 and the piston 60 isnot operated, it may be assumed that pressure was subsequently appliedto the other inlet port via line 45, before the pressure in the timingchamber 55 reached a value of approximately 75 percent of the pressureapplied to the passage 57, via line 45, branch 63-, and single passage62.

Therefore, the head portion 61 is retained in its unoperated positionblocking the passage 59a which passage communicates with the outlet port59 of the master valve 40. Thus, upon pressurizing the passage 57 fromthe inlet port via line 45, the spring-biased check valve 58 responds tothe higher pressure in the passage 57 and thus allows the higherpressure to pass through the open check valve 58 into the timing chamber55, thus equalizing the pressures applied to the head portion 61 and thepiston 60.

Thereafter, as long as pressure is continuously maintained upon thelines 45 and 46, the line 39 will remain pressurized from the passage57.

If pressure is intermittently removed from the inlet port via line 45,such as an intermittent releasing of the manually operable valve 18, theline 45 will be intermittently connected to exhaust, and thereby reducethe pressure in the passage 57 to a value substantially lower than theregulated pressure established and maintained in the timing chamber 55.There fore, the piston 60 will immediately operate, causing the headportion 61 to block the single passage 62, and to vent the passage 57 toexhaust via passage 59a and the exhaust port 59.

A subsequent pressurization of the line 45, while the line 46 has beenretained pressurized, will repressurize the single passage 62, but,because of the area differential between the smaller passage 62 and therelatively larger piston 60, the piston 60 will remain operated to holdthe single passage 62 blocked by the head portion 61, and the passage 57will remain vented to exhaust via passage 59a.

Likewise, if the pressure had been intermittently removed from the otherinlet port of the master valve 40 via line 46, instead of the latterdescribed operation via line 45, the reduced pressure in line 46, spaced50, and branch passage 64, would result in the pass shuttle 51 and thecheck shuttle C each shifting to the right, thus maintaining pressure inthe timing chamber 55 via timing orifice 54, and line 45. The pressurein the branch passage 64, single passage 62, and the passage 57 wouldthen be reduced by reason of the lower pressure in line 46. Therefore,the piston 60 would immediately operate, causing the head portion 61 toblock the single passage 62, and to vent the passage 57 to exhaust viapassage 59a and the exhaust port 59.

As aforesaid, repressurization of the line 46, while line 45 is retainedpressurized, will repressurize the single passage 62, but, because ofthe area differential between the smaller passage 62 and the relativelylarger piston 60, the piston 60 will remain operated to hold the singlepassage 62 blocked by the head portion 61, and the passage 57 vented toexhaust via passage 59a.

Therefore, before the master valve 40 can again be operated via lines 45and 46, both of the manually operable valves 18 and 19 must be released,and thus vent each of the respective lines 45 and 46 to exhaust. Thiswill permit restoration of the piston 60 to the position illustrated inFIG. 4, and to pennit pressurization of the single passage 62 and thepassage 57, by subsequently operating the two manually operable valves18 and 19 either simultaneously, or within one second of one another.

With reference to FIG. 3, it will be apparent that when the outlet portof the master valve 40 is connected to exhaust within the valve, byreason of the operator releasing the lefthand valve 18, the controlvalve 34 is retained operated from the right-hand valve 19, thusresulting in the exhausting of the pilot actuator 33 of the main valve32 via the open connection through the control valve 34 from line 37 toline 39.

Likewise, if the right-hand valve 19 is released before the piston inthe closing cylinder 23 reaches a position beyond the connection of line38a thereto, the connection of line 46 to exhaust, through valve 19,will exhaust the pilot actuator 35 of the control valve 34, causing thevalve 34 to block the connection from line 39 to line 37, and to openits connection from line 38 to line 37. This will connect the pilotactuator 33 of the main valve 34 to exhaust via line 38, and openconnection from line 38 to line 38a within the manual detent valve 94,and by line 38a and its connection to the closing cylinder 23. However,if the right-hand valve 19 is released after the piston in the closingcylinder 23 reaches a position beyond the connection of line 38athereto, the line 380 will receive pressure from the cylinder 23, andthus hold the pilot actuator 33 of the main valve 32 pressurized vialine 38a, the open connection from line 38a to line 38 within the manualdetent valve 34, line 38, the open connection from line 38 to line 37 inthe control valve 34, line 37 and thence to the pilot actuator 33.

This will result in a locking of the head 15 in pressure engagement withthe buck 14. Therefore, to release the locked engagement, a subsequentoperation of the right-hand valve 19 will pressurize the pilot actuator35 of the control valve 34. This will block the connection from line 37to line 38 within the valve 34, and open the connection from line 37 toline 39 therein. Thus, since the line 39 is now connected to exhaustwithin the master valve 40, the pilot actuator 33 of the main valve 32is exhausted.

This will return the main valve 32 to its unoperated position, thusblocking the connection from line a to line 80, and opening theconnection from line 80 to the exhaust port of main valve 32, therebyexhausting the closing and pressure cylinders 23 and 24, in a manner tobe more completely described later.

For clarity, the operation of the described master valve 40, and theassociated right-hand and left-hand manually operated valves 18 and 19may now be reviewed before passing to the description of the remainderof the conduit system.

Accordingly, with a first situation in which the operator first opensvalve 18 with his left-hand, the check shuttle C shifts to the right,and its head 65 blocks airflow from branch passage 63 to a singlepassage 62. The pass shuttle 51 also shifts to the right, passing airfrom line 45 through the timing orifice 54 into the timing chamber 55,and simultaneously blocking flow from space 50 to branch passage 64.Within one second, air pressure in timing chamber 55 reaches its 75percent value which is sufficient to raise piston 60 to cause head 61 toblock any flow from the single passage 62 into passage 57. At this timepassage 57 is vented to the exhaust port 59 via passage 59a. If duringthis l-second period, the operator opens valve 19 with his right hand,air will flow promptly, at full regulated pressure from line 46 intobranch passage 64 and thence into single passage 62, whereupon it willact upon head 61 to retain passage 59a blocked and thus pressurizeoutlet passage 57. The full pressure in passage 57 will unseat checkvalve 58, causing timing chamber 55 to reach instantly full line pres-vsure. With equal pressure applied to head 61 and to piston 60, thepassage 59a remains blocked by the head 61 to block communication ofoutlet passage 57 with exhaust port 59 via passage 59a. At this time,the outlet line 39 supplies pressure into and through the control valve34, via lines 39 and 37, to

the pilot actuator 32 of the main valve 32, which valve is shifted toits second position for the purpose later to be described.

It is apparent that, after having served to supply fluid through line 39to the inlet of the control valve 34, the master valve 40 requires bothits inlet lines 45 and 46 to be exhausted before it is prepared for thenext usage. Thus, the operator necessarily must release both of hishands to permit the manually operated valves 18, 19 to return to theirrespective spring-biased, closed positions before starting the nextoperation of the press.

Taking now, as an example of improper operation, a second situation inwhich the operator waits more than 1 second before opening theright-hand valve 19, after having first opened the left-hand valve 18,it will be seen that the air pressure in the timing chamber 55 acting onthe piston 60, as a result of the left-hand valve 18 having been firstopened, serves to hold the head 61 in raised or closed position,blocking the single passage 62, and also to keep the check valve 58closed. Thus the passage 57 remains vented to the exhaust port 59 viapassage 59a, and no fluid is supplied through line 39 to the inlet ofthe control valve 34.

A third situation, in which the operator first opens valve 19 with hisright-hand, causes the check shuttle C to shift to the left andits headportion 66 to block airflow from branch passage 64 to the single passage62. The pass shuttle 51 also shifts to the left, passing air from line46 through the timing orifice 54 into the timing chamber 55, andsimultaneously blocking airflow from space 50 to branch passage 63.Within 1 second, pressure in timing chamber 55 reaches its 75 percentvalue which is suflicient to raise piston 60 to cause head 61 to blockany flow from the single passage 62 into passage 57. At this timepassage 57 is rented to the exhaust port 59 via passage 59a. If duringthis l-second period, the operator opens valve 18 with his left hand,air will flow promptly, at full regulated pressure, from line 45 intobranch passage 63 and thence into single passage 62, whereupon it willact upon head 61 to retain passage 59a blocked and thus pressurizeoutlet passage 57.

The full pressure in passage 57 will unseat check valve 58, causingtiming chamber 55 to reach instantly full line pressure. With equalpressure applied to head 61 and to piston 60,

the passage 59a remains blocked by head 61 to block communication ofoutlet passage 57 with-exhaust port 59 via passage 59a, and the line 39is pressurized from outlet passage 57. As above indicated, the mastervalve 40 requires both of its inlet lines 45 and 46 to be exhaustedbefore it is prepared for the next usage. Thus, the operator mustrelease both of his hands to permit the manually operated valves 18 and19 to return to their respective spring-biased, closed positions beforestarting the next operation of the press.

Considering as an example of improper operation, a fourth situation inwhich the operator waits more than one second before opening theleft-hand valve 18 after having first opened the right-hand valve 19, itwill be seen that the air pressure in the timing chamber acting upon thepiston 60, as a result of the right-hand valve 19 having been firstopened, serves to hold the head 61 in closed position blocking thesingle passage 62, and also to keep the check valve 58 closed. Thus thepassage 57 remains vented to the exhaust port 59 via passage 59a, and nofluid is supplied through line 39 to the inlet of the control valve 34.

As an example of proper operation, in a fifth situation, in which boththe left-hand and right-hand valves 18 and 19 are opened simultaneously,the heads 65 and 66 of the check shuttle C and the pass shuttle 51, willremain in their respective positions which they occupied at the end ofthe previous operation of the master valve 40. Therefore, if they occupya position with the shuttles shifted to the right, the subsequentoperation will be as defined by the first above situation, and if theyoccupy a position shifted to the left, the-subsequent operation will beas defined by the above third situation.

As will be appreciated, in the operation of the described safety means,the press cannot be operated unless air, at approximately full regulatedline pressure, pressurized the pilot actuator 33 of the main valve 32.

I therefore employ for the protection of a person other than the machineoperator, a safety structure such as shown in FIGS. 1 and 5. Thiscomprises a frame or means 72, 73, 74 and 75 surrounding the movablemember 15 and occupying a predetermined position with respect thereto,note FIG. 5, so that upon its being shifted from the predeterminedposition, when striking an object such as a hand, etc., the movablemember 15 will be released instantly, and unable to continue in itsclosing movement.

One suitable structure includes a rectangular frame having rigid arms70, 71 extending rearwardly from the rear portion 72 of the frame, andpivotally attached to the movable yoke 13, preferably at the axis ofrotation thereof for movement therewith. The front portion 73 and theside portions 74, 75 of the frame are so disposed that they willapproach the press buck 14 in advance of the head 15. Suitably mountedon the yoke 13, for movement therewith, is a two-way bleed valve 76 heldin closed position by the weight of the frame. The exhaust port of thebleed valve 76 is preferably equipped with a suitable muffler orsilencer, and the inlet port is connected by line 77 to the outlet line39 of the master valve 40. The bleed valve 76 may be a Mead Type MV-Shaving its manual actuator 78 held in closed position by the arm 70 ofthe frame, so long as the frame 72, 73, 74 and 75 occupies itspredetermined position with respect to the yoke 13, and to the presshead 15 carried by the yoke.

However, when the frame is raised relative to the yoke and head, themanual actuator 78 is released'by the upward pivotal movement of the arm70, and the valve 76 is opened, thereby venting the lines 77 and 39 toexhaust, and causing the master valve 40 to shift to its positionremoving pressure from line 39 and venting the line 39 to exhaustthrough its passage 59a and exhaust port 59, as hereinbefore describedin detail.

Referring now to H68. 2 and 3, when employed with a garment pressingmachine, the master valve 40, under any of the first, third, or fifthsituations, and with the pilot actuator 35 of the control valve 34pressurized, the pilot actuator 33 of the main control valve 32 ispressurized, thus operating the main valve 32 to its second position. Aslong as the line 37 is held pressurized, either from line 39, or fromline 38, as hereinbefore described in detail, regulated line pressureflows into line 80-80b herein called the second conduit from line 80a.The line 80, 80b has a pressure regulator a, included therein, forregulating the pressure therein flowing to a three-way, normally closedcam valve 27, such as Type OP487 available from the W. M. CissellManufacturing Company, Louisville, Ky.

In such garment presses it is desirable that the speed of the closingcylinder 23 be regulated; that the pressure exerted by the pressurecylinder 24 be related to the fabric of the garment being pressed; thatthe locking or nonlocking of the press head 15, with either a light orheavier pressure engagement with buck 14, be optional with the operator;and that suitable quick exhaust devices be provided for the cylinders 23and 24. The present invention preserves these capabilities whileproviding the described safety features for the operator and otherspresent while the machine is being operated.

A line 81, herein called the first conduit, connects line 80 to thelower end of the closing cylinder 23, below the piston therein, througha conventional Quick Exhaust 82 which may conveniently be the type EVavailable from Deltrol Corporation, Bellwood, Ill., and the exhaust portof the quick exhaust is preferably provided with a suitable muffler orsilencer.

A flow control assembly 83 having a built-in check valve, is interposedin line 81, and the flow control is adjustable to obtain the desiredspeed with which the cylinder 23 moves the head to its closed position.The check valve included in the flow control assembly 83, is springbiased to block airflow from line 80 to line 81, during the period inwhich the closing cylinder 23 is being pressurized, and to permitairflow from line 81 to line 80, when the closing cylinder 23 isexhausted through the exhaust port of the main valve 32, when said valve32 is restored to its unoperated position.

The pressure regulator 85a included in the line 80, 80b has a handle 85,operated by the operator, to adjust pressure to be applied by thecylinder 24 upon the garment being pressed. Ordinarily, the setting ofregulator 85a is made by the operator before he places his hands uponthe manually operated valves 18 and 19. However, the setting of theregulator 85a may be changed, or made, by the operator after the head 15is closed, and-locked in its closed position. A bypass having a checkvalve 86 is connected around the pressure regulator 85a, and this checkvalve is spring biased to block airflow in that bypass from line 80 toline 80b, during the period in which air is flowing to the pressurecylinder 24, and to permit air flow from line 80b to line 80 in thatbypass when the cylinder 24 is exhausted through the exhaust port of themain valve 32, when said valve 32 is restored to its unoperatedposition.

Normally, the three-way, normally closed cam valve 27 vents line 90 tothe exhaust port. However, when the closing cylinder 23 is pressurized,and the press head 15 is moved to a position approximately one-half inchabove the buck 14, the means 25, attached to the piston rod 26, operatesthe cam valve 27, blocking the connection of line 90 to its exhaustport, and opening the connection of line 90 to line 80b, therebypressurizing the cylinder 24 to a value determined by the setting of thepressure regulator 85a. The, pressurizing air flows from line 80 througha conventional quick exhaust 91 which may conveniently be'the TypeEV-250 also available from the Deltrol Corporation, Bellwood, Ill., andthe exhaust .port of quick exhaust 91 is provided with a suitablemuffler or silencer.

A pressure gage 92 is mounted upon the machine, and connected via line92a to the pressure cylinder 24, and this gage indicates to the operatorthe pressure to which the garment is subjected.

i As hereinbefore described, when the press head 15 is moved to aposition approximately one-half inch above the buck 14, the line 38a ischanged from an exhaust condition to a pressurized condition by the flowof air from the closing cylinder 23 to the line 3811. Therefore, if themanual detent reverse flow through lines 90, 80b, and thence through thecheck valve 86, to the exhaust port of valve 32.

Instantly with the establishment of the aforesaid reverse flow of airfrom the cylinders 23 and 24, the quick exhausts 82 and 91 will respondto the reverse flow, and provide a direct venting of cylinder 23 to theexhaust port of quick exhaust 82, and a direct venting of cylinder 2410the exhaust port of the quick exhaust 91. At this time, the press head15 lifts, and the garment may be removed from, or placed in anotherposition upon the buck l4.

In the operation of such presses, the operator is called upon to performvaried duties such as steaming of the garment by operation of footpedals (not shown), and by closing the press head one or more timeswithout actually looking in the closing cylinder 23, or withoututilizing the pressure cylinder 24. Thepresent invention permits suchoperations without jeopardiz ing the safety of the operator. Forexample, the manual detent valve 94 is set to its lock position,blocking the connection of line 38 to the exhaust port of valve 94, andopening the connection of line 38 to line 38a, air will flowfrom line38a to line 38 through the open valve 94 to the inlet connection ofcontrol valve 34. Therefore, when the control valve 34 is returned toits normally open position, blocking the connection of line 37 to line39 and opening the connection of line 37 to line 38, air will flowthrough the open valve 34 to the pilot actuator 33 of the main valve 32.Thus, the operator may now remove his hands from the valves 18 and 19,first valve 18 and then valve 19, and the press head 15 will remainclosed in locked engagement with the buck 14.

As hereinbefore described, when the operator subsequently operates theright-hand valve 19 momentarily, the control valve 34 is operated, andthe pilot actuator 33 of the main valve 32 is exhausted via the openconnection of line 37 to the line 39, which line is now vented to theexhaust port 59 of the master valve 40. The exhausting of the pilotactuator 33 restores the main valve 32 to its normally closed, firstposition,

in which position connection of line 80 to line 80a is blocked,

and the connection of line 80 to the exhaust port of valve 32 is opened.This venting of line 80 to exhaust, will permit air in the closingcylinder 23 to pass in reverse flow through line 81, and thence throughthe-check valve incorporated in the flow control 83, then to exhaustport of valve 32, and at the same time, permit any air in the pressurecylinder 24 to pass in valve, or conventional toggle type lock, nonlockvalve 94, such as Humphrey type l25V3l022-3060, is interposed in theline 38-38a, in its normally open position for locking in. If, however,the operator does not wish the closing cylinder 23 to become locked in,he merely transfers the valve 94 to its closedposition, and the line 38cannotbecome pressurized from line 38a. In this situation, the cylinders23 and 24 are operable to hold the head 15 in engagement with the buck14, either with a light or a heavier pressure, only so long as theoperator keeps his hands on the two valves 18 and 19.

Furthermore, if for some reason, the operator should decide to interruptthe locking in operation of the press head, he may accomplish this byreleasing the left-hand valve 18 before releasing the right-hand valel9, and without transferring the manual detent valve from its lockposition to its nonlock position.

Likewise, if the operator should decide to interrupt the closingmovement of the press head 15, before the piston in the closing cylinder.23 opens pressure communication into line 38a, he may remove either orboth hands from the valves 18 and 19, and the shuttles Cand 51,together. with the piston 60 within the master valve 40, and will shiftautomatically, effecting a depressurizing of the outlet line 39, and theventing of line 39 to the exhaust port 59 of the valve 40,therebyrestoring the main valve 32 to its normally closed first positionin which the connection of line 80 to line 80a is blocked and theconnection of line 80 to the exhaust port of valve 32 is opened. Theaforesaid interruption of the closing movement of the press head l5,will occur, as described, regardless of the position of the manualdetentvalve-94. n 7

In view of the above disclosure, it will be noted that the severalobjectives of the invention are achieved and other advantageous resultsobtained.

What is claimed is:

l. A fluid-operated machine having cooperative members for holding aworkpiece therebetween and comprising in combination, a first actuatorfor closing said members upon the workpiece with a light pressure, asecond actuator for closing said members upon the workpiece with aheavier pressure, and a valve-controlled conduit system connected to asource of pressure fluid and to said first and to said second actuators,said system including a main valve movable between a normal firstposition blocking the supply of fluid to said actuators and a secondposition for supplying fluid to said actuators, said main valve having apilot actuator adapted when pressurized with fluid to move said mainvalve into and to hold it in said second position and when vented topermit return of said main tuator, the flow of fluid from said mastervalve being initiated only when said manually operated valves areoperated within a predetermined time interval of each other, means foractuating said second actuator, and means for passing fluid from saidfist actuator through said control valve into said pilot actuator assaid members are brought into proximity to each other by said firstactuator.

2. A fluid-operated garment press equippedwith a safety control systemand comprising in combination, a buck, a movable press head, a firstactuator and a second actuator for closing said head upon said buckrespectively with a light pressure and with a heavier pressure, and avalve-controlled conduit system connected to a source of pressure fluidand to said actuators, said system including a main valve movablebetween a normal first position blocking the supply of fluid to saidactuators and a second position for supplying fluid to said actuators,said main valve having a pilot actuator adapted when pressurized to movesaid main valve into and hold it in said second position and when ventedto permit return of said main valve to its first position, a controlvalve for controlling the pressurizing and venting of said pilotactuator, and a safety' control means including a master valve andspaced right-hand and left-hand manually operable valves, said mastervalve being adapted to receive fluid jointly from said manually operablevalves and to pass fluid into said control valve and thence to saidpilot actuator thereby to effect actuation of said first actuator at thebeginning of a pressing operation, the flow of fluid from. said mastervalve to said control valve being initiated only when said manuallyoperated valves are operated within a predetermined time interval ofeach other, means for actuating-said second actuator, and means forpassing fluid from said first-actuator through said control valve andinto said pilot actuator following the closing of said head upon saidbuck by said first actuator.

3. A garment press as defined in claim 2 wherein said conduit systemincludes first and second conduits extending respectively from said mainvalve to said first and said second actuators, and a third conduitextending from said first actuator to said control valve, said thirdconduit being adapted to receive fluid only when said head moves intoproximity to said buck.

4. A garment press as defined in claim 3 including in said secondconduit a normally closed valve actuated automatically in dependenceupon the movement of said press head and adapted when opened to supplyfluid to said second actuator.

S. A garment press as defined in claim 3 including a manually operablevalve in said third conduit movable between a first position ventingsaid third conduit, and a second position establishing a flow connectionbetween said first actuator and said control valve.

6. A garment press as defined in claim 3 including a flow control meansin said first conduit and adapted to regulate the speed of movement ofsaid first actuator during movement of said press head toward said buck.

7. A garment press as defined in clam 3 including a pressure regulatingmeans in said second conduit and adapted to regulate the pressure offluid supplied to said second actuator thereby to provide a selectedpressure of said press head upon said buck. v

1. A fluid-operated machine having cooperative members for holding aworkpiece therebetween and comprising in combination, a first actuatorfor closing said members upon the workpiece with a light pressure, asecond actuator for closing said members upon the workpiece with aheavier pressure, and a valve-controlled conduit system connected to asource of pressure fluid and to said first and to said second actuators,said system including a main valve movable between a normal firstposition blocking the supply of fluid to said actuators and a secondposition for supplying fluid to said actuators, said main valve having apilot actuator adapted when pressurized with fluid to move said mainvalve into and to hold it in said second position and when vented topermit return of said main valve to its first position, a control valvefor controlling the pressurizing and venting of the said pilot actuator,a safety means including a master valve and spaced right-hand andleft-hand manually operable valves, said master valve being adapted toreceive fluid jointly from said manually operable valves and to passfluid into said control valve and thence to said pilot actuator therebyto effect operation of said first actuator, the flow of fluid from saidmaster valve being initiated only when said manually operated valves areoperated within a predetermined time interval of each other, means foractuating said second actuator, and means for passing fluid from saidfirst actuator through said control valve into said pilot actuator assaid members are brought into proximity to each other by said firstactuator.
 2. A fluid-operated garment press equipped with a safetycontrol system and comprising in combinaTion, a buck, a movable presshead, a first actuator and a second actuator for closing said head uponsaid buck respectively with a light pressure and with a heavierpressure, and a valve-controlled conduit system connected to a source ofpressure fluid and to said actuators, said system including a main valvemovable between a normal first position blocking the supply of fluid tosaid actuators and a second position for supplying fluid to saidactuators, said main valve having a pilot actuator adapted whenpressurized to move said main valve into and hold it in said secondposition and when vented to permit return of said main valve to itsfirst position, a control valve for controlling the pressurizing andventing of said pilot actuator, and a safety control means including amaster valve and spaced right-hand and left-hand manually operablevalves, said master valve being adapted to receive fluid jointly fromsaid manually operable valves and to pass fluid into said control valveand thence to said pilot actuator thereby to effect actuation of saidfirst actuator at the beginning of a pressing operation, the flow offluid from said master valve to said control valve being initiated onlywhen said manually operated valves are operated within a predeterminedtime interval of each other, means for actuating said second actuator,and means for passing fluid from said first actuator through saidcontrol valve and into said pilot actuator following the closing of saidhead upon said buck by said first actuator.
 3. A garment press asdefined in claim 2 wherein said conduit system includes first and secondconduits extending respectively from said main valve to said first andsaid second actuators, and a third conduit extending from said firstactuator to said control valve, said third conduit being adapted toreceive fluid only when said head moves into proximity to said buck. 4.A garment press as defined in claim 3 including in said second conduit anormally closed valve actuated automatically in dependence upon themovement of said press head and adapted when opened to supply fluid tosaid second actuator.
 5. A garment press as defined in claim 3 includinga manually operable valve in said third conduit movable between a firstposition venting said third conduit, and a second position establishinga flow connection between said first actuator and said control valve. 6.A garment press as defined in claim 3 including a flow control means insaid first conduit and adapted to regulate the speed of movement of saidfirst actuator during movement of said press head toward said buck.
 7. Agarment press as defined in claim 3 including a pressure regulatingmeans in said second conduit and adapted to regulate the pressure offluid supplied to said second actuator thereby to provide a selectedpressure of said press head upon said buck.